The CAP Theorem states that it is possible to optimize for any 2 of Consistency, Availability, and Network Partition Tolerance, but not all three. Though presented by Eric Brewer in 2000 and proved in 2002, the CAP Theorem has only recently gained significant awareness and that primarily among engineers working on high-traffic applications. With spreading awareness of the CAP theorem, there has been a proliferation of development on AP (a.k.a. Available-Network Partition Tolerant) systems - systems that offer weaker consistency guarantees for higher availability and network partition tolerance. Much of the interest in these AP systems is in the social networking and web entertainment space where eventual consistency issues are relatively easy to mask. Netflix is one company that is embracing AP systems. This paper addresses Netflix's transition to AWS SimpleDB and S3, examples of AP storage systems.
The full text for this paper is available here: Netflix's Transition to High-Availability Storage Systems